The following is based on Van Buren and has not been confirmed by canon sources.

Successfully get regular shipments from Denver for materials to build hydroponics lab in Scum Pits was going to be a quest in Van Buren, the canceled Fallout 3 by Black Isle Studios.

Walkthrough

Once the player figures out that Denver is a cache for building materials, the player will need to inform one of the still existing caravans about the need to pick up materials. This quest only comes up after the player clears out the critters in the Scum Pits and has conversed with Governor Dodge. This way one of the two caravans will be in control and approachable.